{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{6}{c}}
\hline\hline
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}&\multicolumn{1}{c}{(5)}&\multicolumn{1}{c}{(6)}\\
                    &\multicolumn{1}{c}{Q15}&\multicolumn{1}{c}{Q15}&\multicolumn{1}{c}{Q18}&\multicolumn{1}{c}{Q18}&\multicolumn{1}{c}{Q19}&\multicolumn{1}{c}{Q19}\\
\hline
Republican          &        0.17\sym{***}&        0.19\sym{***}&        0.07\sym{*}  &        0.02         &        0.05         &       -0.01         \\
                    &      (0.03)         &      (0.05)         &      (0.03)         &      (0.04)         &      (0.03)         &      (0.05)         \\
Other-party Extremism&       -0.06\sym{+}  &       -0.04         &                     &                     &                     &                     \\
                    &      (0.03)         &      (0.04)         &                     &                     &                     &                     \\
Gridlock            &       -0.05         &       -0.04         &                     &                     &                     &                     \\
                    &      (0.03)         &      (0.04)         &                     &                     &                     &                     \\
Rep $\times$ Other-party Extremism&                     &       -0.06         &                     &                     &                     &                     \\
                    &                     &      (0.07)         &                     &                     &                     &                     \\
Rep $\times$ Gridlock&                     &       -0.00         &                     &                     &                     &                     \\
                    &                     &      (0.07)         &                     &                     &                     &                     \\
Co-partisan         &                     &                     &        0.65\sym{***}&        0.61\sym{***}&        0.42\sym{***}&        0.38\sym{***}\\
                    &                     &                     &      (0.03)         &      (0.04)         &      (0.03)         &      (0.04)         \\
Blocked, Voter Protest&                     &                     &       -0.82\sym{***}&       -0.83\sym{***}&       -0.62\sym{***}&       -0.62\sym{***}\\
                    &                     &                     &      (0.05)         &      (0.05)         &      (0.05)         &      (0.05)         \\
Blocked, Court Action&                     &                     &       -1.01\sym{***}&       -1.02\sym{***}&       -0.84\sym{***}&       -0.84\sym{***}\\
                    &                     &                     &      (0.05)         &      (0.05)         &      (0.05)         &      (0.05)         \\
Succeeded           &                     &                     &       -0.71\sym{***}&       -0.71\sym{***}&       -0.49\sym{***}&       -0.49\sym{***}\\
                    &                     &                     &      (0.04)         &      (0.04)         &      (0.04)         &      (0.04)         \\
Republican $\times$ Co-partisan&                     &                     &                     &        0.10         &                     &        0.11         \\
                    &                     &                     &                     &      (0.06)         &                     &      (0.07)         \\
Constant            &        1.86\sym{***}&        1.85\sym{***}&        2.46\sym{***}&        2.48\sym{***}&        2.57\sym{***}&        2.59\sym{***}\\
                    &      (0.02)         &      (0.03)         &      (0.04)         &      (0.04)         &      (0.04)         &      (0.04)         \\
\hline
Observations        &        4349         &        4349         &        3429         &        3429         &        3414         &        3414         \\
\(R^{2}\)           &       0.009         &       0.009         &       0.240         &       0.241         &       0.138         &       0.139         \\
\hline\hline
\multicolumn{7}{l}{\footnotesize Standard errors in parentheses}\\
\multicolumn{7}{l}{\footnotesize \sym{+} \(p<0.10\), \sym{*} \(p<0.05\), \sym{**} \(p<0.01\), \sym{***} \(p<0.001\)}\\
\end{tabular}
}
